Permutation lock



' Dec. 2?, 1932. E B, T N 1,892,290

PERMUTATI ON LOCK Filed May 12, 1931 Patented Dec. 27, 1932 UNETED STATES PATENT OFFICE ELMER B. STONE, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE AMERICAN HARDWARE CORPORATION, OF NEW BRITAIN, CONNECTICUT, A CORPORATION OF CONNECTICUT PER/MUTATION LOCK Application filed May 12,

My invention relates to the class of locks embodying tumblers that are moved into registering positions as by means of a knob or similar device to permit action of a releasing member, and an object of my invention, among others, is to provide means whereby locking members cannot be operated except by the means provided for that purpose.

One form of a lock embodying my invention and in the construction and use of which the objects herein set out, as well as others, may be attained, is illustrated in the accompanying drawing, in which Figure 1 is a front view of a padlock embodying my improvement with parts broken away to show construction.

Figure 2 is an edge view, scale enlarged, of my improved lock with parts broken away to show construction.

Figure 3 is a detail view in section on a plane denoted by the dotted line 33 of Figure 2 but illustrating only the operating spindle and a tumbler thereon.

In the accompanying drawing the numeral 5 denotes the case of my improved lock which, in the form herein illustrated, is of the padlock type having a shackle 6 of any ordinary and well-known construction, one arm 7 of which extends into the case and is secured therein for lengthwise movement, the other arm 8 being engaged with a locking member within the ca se in a manner that will be readily understood and for which reason a further and detailed description is omitted herein, further than to say that this locking memher 9 has a prong 10 that is adapted to be engaged in notches 11 in a series of tumblers 12, when all of said tumblers are in such positions that the notches register one with another so that the prong 10 may project into the notches in all of the tumblers, as disclosed in my co-pending application hereinafter mentioned. These tumblers are mounted upon an arbor 13 which is operated as by means of a knob 1d that is commonly rotated success vely in opposite directions to bring the tumblers into the registering positions hereinbefore mentioned. The knob and the tumblers are adapted to be connected as by means of lugs 15 projecting from the tum- 1931. Serial No. $6,699.

blers and engaged in a manner that will be readily understood by those skilled in the art and for which reason a further and detailed description is omitted herein.

IV hen the shackle is moved to its closed and locking position one or more of the tumblers are turned from its or their position or positions of registry with the prong 1G, and this effect may be accomplished in different ways, in some cases the knob 14 being used for this purpose, and in other cases the shackle being provided with means for engagement with a tumbler or tumblers to disarrange the latter as the shackle is moved to its closed position as disclosed in my co-pending application filed December 5, 1930 of S. No. 500,224.

It is possible, in locks of this type, by the application of repeated blows in a certain position on the lock case to vibrate the structure so that a tumbler or tumblers may be brought into unlocking position or positions, and this is particularly true where a single tumbler only has been disarranged. It is the purpose of the present invention to provide means for preventing this unauthorized manipulation of the lock.

In accomplishing this purpose I provide the arbor 13 with a number of ribs 16 thereby creating grooves between the ribs, and I also provide one or more of the tumblers 12 with grooves 17 to receive the ribs 16. In other words, the arbor has ribs to be received in grooves in the tumbler or tumblers and the latter have ribs to be received in grooves in the arbor. Space enough is created between the arbor and the tumblers to permit the latter to be rotated independently of the arbor when a little force is applied to the tumblers by operation of the knob 14, such force being transmitted through the engaged lugs 15 in the manner common to locks of this type, the ribs in one member in such case being readily forced from the grooves in the other member. The space between the arbor and the tumblers is exaggerated in Figure 3 of the drawing in order to clearly bring out the purpose and feature of the invention and this is also true as to the dimensions of the grooves and ribs which, in actual practice, are minute.

It will be understood, however, that the space between the arbor and the tumblers is very slight and such as not to interfere with the ordinary operation of the tumblers which are free to rotate on the arbor. The interengaging ribs and grooves on the arbor and tumblers are also minute and such as to permit the tumblers to be rotated independently of the arbors. These engaged ribs and grooves, however, are sufficient to impose enough friction so that rotation of the tumblers independently of the arbors will be prevented if abnormal means are employed to effect this result.

From this it will be noted that if a blow be delivered upon the case for the purpose of rotating a tumbler or tumblers such blow will force a rib on one member into a groove in the other member and will thereby prevent rotation of the tumbler as a result of the blow, and it will therefore be seen that this means of surreptitiously operating the lock will not be effective for the reason that the tumblers may not by this means he brought into unlocking positions.

In accordance with the provisions of the patent statutes I have described the principles of operation of my invention together with the device which I now consider to represent the best embodiment thereof; but I desire to have it understood that the device shown is only illustrative, and that the invention may be carried out by other means and applied to uses other than those above set out.

I claim:

1. A look including an arbor, ribs extending lengthwise of said arbor, tumblers mounted on said arbor for rotation thereon independently thereof, and having notches to receive said ribs, to obstruct rotating-movement of said tumblers but to be frictionally released therefrom to permit normal rotation of the tumblers for unlocking operation, and means for rotating said tumblers.

2. A lock including an arbor, tumblers mounted on said arbor and having a limited lateral movement thereon, interengaging ribs and grooves on the tumbler and arbor to restrain the tumbler from rotation but to permit its rotation independently of the arbor upon the application of force thereto, said ribs being rounded on their outer edges to permit such rotation, and means for rotating said tumblers.

ELMER B. STONE. 

